1. Technical Field
The present disclosure relates to an audio amplifier circuit and method of operation thereof.
More particularly, but without limitation, the circuit and method find their use in audio amplifiers designed for use in the automotive industry.
2. Description of the Related Art
In the field of automotive audio amplifiers, i.e., in the car audio industry, there is currently a strong need to achieve a high efficiency or, equivalently, a low consumption in terms of power not converted into sound pressure.
This need is particularly felt with the recent launch of electrically powered cars. In this type of cars the need of saving power is a particularly stringent requirement, because power savings increase the endurance of a car, thereby improving its usability.
For these reasons, manufacturers increasingly tend to install high-efficiency amplifiers in electrically powered cars, such as switching amplifiers or D class amplifiers.
Another source of power loss, which is not negligible in music, is quiescent current.
For instance, an amplifier supplied with a typical automotive battery voltage supply, i.e., 14.4V, dissipates energy even when it does not deliver power. The dissipated power may be estimated to be about 0.5-1 W per channel, even when power is not delivered through a channel of the amplifier.
It will be understood that such consumption may affect the endurance of electrically powered cars even to a considerable extent and/or, more generally, may increase consumption and hence CO2 emissions in conventionally powered and/or hybrid powered cars.